{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "4.6.0"
              },
              {
                "fixed": "4.6.3"
              },
              {
                "introduced": "4.7.0"
              },
              {
                "fixed": "4.7.4"
              },
              {
                "introduced": "4.8.0"
              },
              {
                "fixed": "4.8.1"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "58defb7424773c75718f0173f4ace702cffa4f0e"
            },
            {
              "fixed": "af9e5773f1b33576d59a62c5a769e0aa72e232dd"
            },
            {
              "introduced": "9360131992064203f9ee46fa0504d20276c97339"
            },
            {
              "fixed": "2b06c0db46104a72dcbb8f47b3d501b9abb29228"
            },
            {
              "introduced": "d1ed79a66c7930020b7fda046a11050f5890c84e"
            },
            {
              "fixed": "6dc9fa885dfd5448fb6910bfb0cb4f1179139ff8"
            }
          ],
          "repo": "https://github.com/mattermost/mattermost",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {},
  "details": "An issue was discovered in Mattermost Server before 4.8.1, 4.7.4, and 4.6.3. WebSocket events were accidentally sent during certain user-management operations, violating user privacy.",
  "id": "CVE-2018-21260",
  "modified": "2026-07-08T05:39:17.002893482Z",
  "published": "2020-06-19T17:15:12.897Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://mattermost.com/security-updates/"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}